Many pneumatic devices, such as an inflators, pressure washers, paint sprayers, and others, operate under compressed air that is stored in a tank. The tank is filled to an elevated storage pressure level that is greater than the pressure level needed for any particular application, such as inflating tires. This enables the user to draw compressed air from the tank as long as the storage pressure remains above the level needed by the user. The device typically has a control valve assembly for controlling the flow of air into and out of the tank.